Carefully cut off 1-inch top of angel food cake; set aside. Cut down into cake and gently remove core of cake, leaving a 1-inch thick border from bottom and around sides. Crumble cored cake into small pieces.
In a medium bowl, stir together cake pieces, cream cheese, brown sugar, pecans, and cinnamon.
Fill center ring of angel food cake with mixture. Place cake top back on.
Frost cake with whipped topping. Garnish with chopped pecans and ground cinnamon.